diff --git a/dtls/test/unit.py b/dtls/test/unit.py
index f1b386e..8e82313 100644
--- a/dtls/test/unit.py
+++ b/dtls/test/unit.py
@@ -281,7 +281,7 @@ class NetworkedTests(unittest.TestCase):
                     count += 1
                     s.do_handshake()
                     break
-                except ssl.SSLError, err:
+                except ssl.SSLError as err:
                     if err.args[0] == ssl.SSL_ERROR_WANT_READ:
                         while True:
                             to = s.get_timeout()